<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">1. People will find .none ugly which is why I think it could be replaced by a none keyword. It is awkward<div class="">2. none is more descriptive than nil in this case. The case is named none (consistency!) and nil is a holdover from other languages</div><div class=""><br class=""></div><div class="">I understand how nil works in the context of other languages. But looking at Optional:</div><div class=""><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">public</span><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">enum</span><span style="font-variant-ligatures: no-common-ligatures" class=""> Optional<Wrapped> : </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">NilLiteralConvertible</span><span style="font-variant-ligatures: no-common-ligatures" class=""> {</span></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">/// The absence of a value.</span></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #008400" class="">///</span></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">/// In code, the absence of a value is typically written using the `nil`</span></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">/// literal rather than the explicit `.none` enumeration case.</span></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">case</span><span style="font-variant-ligatures: no-common-ligatures" class=""> none</span></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo; min-height: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">/// The presence of a value, stored as `Wrapped`.</span></div><div style="margin: 0px; font-size: 12px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">case</span><span style="font-variant-ligatures: no-common-ligatures" class=""> some(Wrapped)</span></div><div class="">}</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">These are not pointers and they sure look like one when you assign nil to an optional</div><div class=""><br class=""></div><div class="">B</div><div class=""><br class=""></div><div class="">Why would nil be chosen to represent the none case in the absence of other languages?</div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Jun 8, 2016, at 4:55 PM, Sean Heber <<a href="mailto:sean@fifthace.com" class="">sean@fifthace.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">If you add a new keyword called “none” without the period, but keep allowing “.none” to work because Optional is really an enum… then I don’t really see what has been gained here at all - you’re basically back to nil/.none => 2 ways to say the same thing!<br class=""><br class="">l8r<br class="">Sean<br class=""><br class=""><br class=""><blockquote type="cite" class="">On Jun 8, 2016, at 3:52 PM, Brandon Knope via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""><br class="">.none or a more appropriate keyword like “none” (imo)<br class=""><br class="">Brandon<br class=""><br class=""><blockquote type="cite" class="">On Jun 8, 2016, at 4:47 PM, Xiaodi Wu via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""><br class="">It's been pointed out before that Optional being an enum type is treated like an implementation detail. Currently, it is possible to teach the concept of Optional without introducing enum types or generics. How would you do so after elimination of nil?<br class=""><br class=""><br class="">On Wed, Jun 8, 2016 at 3:41 PM, Антон Жилин <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class="">(No joking)<br class="">Points:<br class=""><br class="">1. When nil was added to the language, we could not infer enumeration type:<br class="">if x != Optional.none { ... }<br class=""><br class="">Now it looks like this:<br class="">if x != .none { ... }<br class=""><br class="">If at this point we had a proposal to add nil as a replacement for .none, would we accept it?<br class=""><br class="">2. nil is very generic, it only approximately allows to express the intentions.<br class="">In case of Optional, .none is clearer. In case of JSON processing, .null is clearer. In case of a semantically nullable struct, NilLiteralConvertible usually goes to default constructor.<br class=""><br class="">3. Too many "empty" things: .none, nil; NSNull, Void, NoReturn types.<br class=""><br class="">4. There should be a single consistent terminology: no value in Swift equals none.<br class=""><br class="">- Anton<br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class="">https://lists.swift.org/mailman/listinfo/swift-evolution<br class=""><br class=""><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class="">swift-evolution@swift.org<br class="">https://lists.swift.org/mailman/listinfo/swift-evolution<br class=""></blockquote><br class="">_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class="">https://lists.swift.org/mailman/listinfo/swift-evolution<br class=""></blockquote><br class=""></div></div></blockquote></div><br class=""></div></div></body></html>